I recommend the government__________ Real Cine for urban planning since it is cheaper and practical, the way most urban planning is done today.
A:uses; compared to
B:use; compared with
C:use; comparing to
D:uses; comparing with
“我们不把任何未经验证的意见接受作为真理,而是遵照必要的次序,从一步推演到下一步……不论多么深奥,最终都能发现。”与这句话的理念一致的说法是( )
黑火药是中国古代的四大发明之一,其爆炸的热化学方程式为:
S(s)+2KNO3(s)+3C(s)═K2S(s)+N2(g)+3CO2(g)△H=x kJ•mol﹣1
已知碳的燃烧热△H1=a kJ•mol﹣1
S(s)+2K(s)═K2S(s)△H2=b kJ•mol﹣1
2K(s)+N2(g)+3O2(g)═2KNO3(s)△H3=c kJ•mol﹣1
则x为( )
设平面向量a→=(x1,y1),b→=(x2,y2),定义运算⊙:a→⊙b→=x1y2﹣y1x2.已知平面向量a→,b→,c→,则下列说法错误的是( )